After a week of pressure and criticism, the Oscar-winning US actress Hilary Swank has agreed to donate to charity the fee she received for eulogising Chechnya's warlord leader.

Swank was at a party in Grozny last week to mark Ramzan Kadyrov's 35th birthday, along with Jean Claude Van Damme, violinist Vanessa Mae and the singer Seal.

The star of Million Dollar Baby, 37, had been told by human-rights groups about allegations of the widespread torture and extrajudicial killings carried out by forces loyal to the Kremlin-backed Mr Kadyrov. He has praised those who fired paintball guns at women without headscarves, and said women wearing skirts above the knee will "go to hell".

Despite the warnings, Swank and the other stars attended the concert. From a specially erected floating stage, she praised Mr Kadyrov and said she could see "everyone was happy" in Chechnya.

Amid a flurry of criticism, she backtracked on Thursday and said she "deeply regrets" her participation in the event. But she stopped short of saying she would return the money.

This prompted a statement from the Human Rights Foundation, calling her response "weak". Yesterday, Swank's agent said she would donate her fee "to various charitable organisations". There has been no confirmation of exactly how much money she received for her gushing praise of Mr Kadyrov, but Mae is rumoured to have received more than £300,000, and Swank's fee is believed to have been even larger.

The other Western stars to take part in the show have made no comment except Seal, who has stood by his involvement and hit out at critics on Twitter.

Mr Kadyrov gave his first comments about the event in an interview with Russian newspaper Komsomolskaya Pravda yesterday. He said payments for Swank and others were covered by sponsors and investors, rather than coming from the public purse.

Mr Kadyrov said before last week's gala that he did not want lavish celebrations for his birthday. He threatened to fire officials who gave him presents. The celebrations were ostensibly to mark Grozny's City Day, which was moved to coincide with Mr Kadyrov's birthday. But nobody was in doubt about the real nature of the celebration, and Swank cooed "Happy Birthday, Mr President" when on stage. She later said she was told to say this by concert organisers.

Chechen TV also showed footage of celebrations at Mr Kadyrov's family mansion, where he arrived to a firework display and received a house-sized model of a mosque made from flowers.